A fuel supply system for a gas turbine typically includes a fuel shutoff valve to interrupt fuel supply to the combustion chamber of the gas turbine. A fuel supply system for certain gas turbines is provided in a compact fuel module, which constitutes a complete fuel system from fuel inlet to the fuel gas manifold of the combustion chamber. Certain safety standards, such as ATEX (ATmosphere EXplosibles) and CSA (Canadian Standards Association) standards, require installation of shutoff valves on liquid fuel supply lines with open/closed valve position indicators.
U.S. Pat. No. 6,481,459 issued to Fukano et al. (“the '459 patent”) discloses an example of a valve assembly with an indicator section for indicating an ON/OFF state of the valve. A two-way valve has a diaphragm for opening and closing a fluid passage. An indicator of the indicator section, provided in the upper part of the two-way valve, is connected to the diaphragm via two rods so that the indicator is displaced in unison with the diaphragm. Displacement of these rods is directly transmitted to the indicator section to indicate whether the two-way valve is in the ON state where the fluid passage is opened or in the OFF state where the fluid passage is closed.